An electronic control unit (ECU) is control units configured to control and manage main assemblies of a vehicle. Among ECUs, a multi-core ECU may include an ECU core configured to control and manage assemblies, a peripheral control processor (PCP) core configured to monitor and evaluate functional defects of the ECU core, and a watchdog device independently configured to control the ECU. In general, a watchdog device is disposed inside a vehicle and implemented according to the ISO26262 standard.